During installation of Ubuntu 16.04.2 desktop amd64 to the hard drive, the Install window said this in the fourth step: "This computer currently has no detected operating systems." There was indeed an OS already on the HDD; I had used it only a few hours earlier. It was Fedora 26. Therefore, the message misinformed the user. I don't know if the cause was a difference in filesystems at the level of platter sector formatting. Nonetheless, it should warn the user that there might be an OS or data even though the Ubuntu installation can't see it. That would give the user a chance to remember to back up the data or to manually reconfigure the HDD to keep the old OS when allowed.
I have cold-rebooted multiple times before reporting this, so I don't have the logs you prefer. Also, a search does not produce System or lsb_release -rd and a CLI terminal tells me that no LSB modules are available.
Unfortunately, without logs or the ability to perform any further investigation, we won't be able to work on this issue.